Intelligent automated assistants (or digital assistants) can provide a beneficial interface between human users and electronic devices. Such assistants can allow users to interact with devices or systems using natural language in spoken and/or text forms. For example, a user can provide a speech input containing a user request to a digital assistant operating on an electronic device. The digital assistant can interpret the user's intent from the speech input, operationalize the user's intent into a task, and perform the task. In some systems, performing tasks in this manner may be constrained in the manner by which a task is identified. In some cases, however, a user may be limited to a particular set of commands such that the user cannot readily instruct a digital assistant to perform a task using natural-language speech inputs. Further, in many instances digital assistants fail to adapt based on previous user behavior and in turn lack a desirable optimization of user experience.